Since 1946, the San Diego Museum of Art has owned an appealing vision of happy prosperity: Frans Hals' 1630s painting of a plump, rosy-cheeked Dutch merchant whose expression and body language exude confidence, security and bonhomie.

In the early 1990s, on one of his infrequent visits to Los Angeles from Europe, Bernard Goodman asked his son, Simon, to take him to see it. Standing in front of the portrait of Isaac Abrahamsz Massa, Bernard for the first time permitted a crack in what his son calls "the brick wall of silence" that had confronted him and his older brother, Nick, all their lives.

Growing up in London after World War II, the Goodman brothers learned only after they were in their teens that their grandparents had been murdered by the Nazis and that their father was the dispossessed scion of one of the great banking families of Holland and Germany.

But Bernard kept from his sons the anguished, needle-in-a-haystack search he conducted from 1945 to about 1955 for the fabulous art collection the Nazis had stolen from their grandparents.

The Dutch estate of Friedrich "Fritz" Gutmann and Louise Gutmann von Landau had housed Old Master and Impressionist paintings — among them the Frans Hals portrait — as well as sculpture, Louis XV furniture, elegant Chinese porcelain and dazzling gold and silver clocks, vessels and tableware.

Bernard, his sons would learn much later, had limited success in recouping their grandparents' art after the war. He sold most of what he recovered to keep his now-struggling family going, sharing the proceeds with his sister, Lili.

As father and son stood in the museum gallery in San Diego, Simon Goodman recalled, "that painting started my dad talking a little. He started to open up — not too much, but he was just slightly emotional. It reinforced the concept that we'd lost everything."

Bernard Goodman died in 1994 in Germany, where, to his sons' great surprise, he'd settled after kindling a late-in-life romance with a German woman. She sent the contents of his desk to L.A., where Simon, now 66, has lived since transplanting the rock music importing and distribution business he'd owned from London in 1979. Nick, 68, is an art director for films and commercials who came to the U.S. in 1969.

Their father, who'd been studying at at Cambridge University before the war, then enlisted in the army, left correspondence, photographs and other records he had kept, finally giving the brothers a window on his search for missing art.

"Some families were so damaged that they didn't want to go back" where tragedy had overtaken them, Simon Goodman said. "My father was brave. He took the first boat to Holland after the war and started knocking on doors. Things dried up, eventually," but about 40 years later, Bernard's carefully kept records would contain enough clues for his sons to pick up the search.

For the most part, their father had recovered artworks initially rescued in France and Germany from 1944 to 1946 by art specialists attached to the U.S. Army — the units whose story inspired George Clooney's recently released film, "The Monuments Men."

"The problem, going back to the Monuments Men, is that nobody made any serious attempt to finish the job thoroughly," said Simon Goodman.

Under Allied policy, the military's art specialists — officially Monuments, Fine Arts and Archives units — sent their finds back to where they'd been before the war. It was left to each postwar government in Western Europe to restore the art to its owners or their heirs — if they were alive and could produce proof of who they were and what they'd owned.

Claimants faced daunting obstacles, including property laws that gave no special consideration to things the Nazis had stolen. In some nations, families that had been forced to sell art to Nazi agents for a pittance were out of luck because the legal codes said a sale was a sale, never mind the circumstances.

Jews had been the particular targets of art looting, and many of those who survived the war did not return to their former homelands. The Goodmans, who weren't religious, had in fact converted to Lutheranism in the 19th century, hoping it would help in the face of rising European anti-Semitism. The distinction was lost on the Nazis.

Some restitution experts say it was necessary for the Americans and British to trust the legal systems of nations not known for their goodwill toward Jews: "It would have been impossible, not just impractical, to do anything else" because of the costs and legal and logistical complexities of running a claims clearinghouse for all of Western Europe, said Thomas Kline, an art-restitution lawyer in Washington, D.C., who represented Nick and Simon Goodman in their first important recovery case.

Rose Valland, a French curator on whom Cate Blanchett's character in "The Monuments Men" is based, was Bernard Goodman's chief angel, to the extent he found any. She had spied on the Nazis as they hoarded looted Jewish art from across the Continent at the Jeu de Paume museum in Paris.